Traversing a Dictionary

Traversing a dictionary means visiting each of its items one by one — and the tool for that is the for loop. The textbook shows two equivalent methods.

Start with a dictionary of students and their marks:

>>> marks = {'Anita': 95, 'Bala': 89, 'Chetan': 92, 'Divya': 85}

Method 1 — loop over the keys

Looping over a dictionary directly yields its keys; each value is then looked up inside the loop using dict[key]:

>>> for key in marks:
...     print(key, ':', marks[key])

Anita : 95
Bala : 89
Chetan : 92
Divya : 85

Method 2 — loop over key-value pairs with items()

The items() method yields each item as a (key, value) pair, which the loop header unpacks into two variables at once — no separate lookup needed:

>>> for key, value in marks.items():
...     print(key, ':', value)

Anita : 95
Bala : 89
Chetan : 92
Divya : 85
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